Tuyere for a melting furnace

ABSTRACT

A tuyere for a melting furnace, which comprises inner and outer walls forming a water cooling space therebetween; a cylindrical intermediate wall dividing the water cooling space into an inner water cooling chamber and an outer water cooling chamber, wherein water is introduced into the outer water cooling chamber from the outside of the furnace, circulated into the inner water cooling chamber from the inner end portion at the furnace side of the outer water cooling chamber and discharged from the outer end portion of the inner water cooling chamber; and a guide wall disposed in the water cooling chambers, whereby water circulates at a high speed at least in the portions of the water cooling chambers which are disposed inside the melting furnace.

United States Patent [191 Ikegawa [11] 3,826,479 [451 Ju1y30, 1974TUYERE FOR A MELTING FURNACE [75] Inventor: Kiyohiro lkegawa, Nara,Japan [73] Assignee: Kurimoto Iron Works, Ltd.,

Osaka-fu, Japan [22] Filed: Feb. 16, 1973 [21] Appl. No.: 333,314

[52] US. Cl. 266/41, 110/1825 [51] Int. Cl C21b 7/16 [58] Field ofSearch 239/1323; 122/66;

[56] References Cited UNITED STATES PATENTS 2.735,4()9 2/1956 Aurin cta1 266/41 3,052,219 9/1962 Huuck 122/66 3.599.951) 8/1971 Tundcr.....266/41 3,627,296 12/1971 Ucrlichs.... 266/41 3,638,929 2/1972 Brulhet266/41 FOREIGN PATENTS OR APPLICATIONS 77.366 9/1954 Netherlands239/1323 Primary Examiner-Gerald A. Dost Attorney, Agent, orFirm-Woodhams, Blanchard and Flynn [57] ABSTRACT A tuyere for a meltingfurnace, which comprises inner and outer walls forming a water coolingspace therebetween; a cylindrical intermediate wall dividing the watercooling space into an inner water cooling chamber and an outer watercooling chamber, wherein water is introduced into the outer watercooling chamber from the outside of the furnace, circulated into theinner water cooling chamber from the inner end portion at the furnaceside of the outer water cooling chamber and discharged from the outerend portion of the inner water cooling chamber; and a guide walldisposed in the water cooling chambers, whereby water circulates at ahigh speed at least in the portions of the water cooling chambers whichare disposed inside the melting furnace.

2 Claims, 10 Drawing Figures PATENTEB M30374 SHEEI 1 [IF 4 PATENTEM L3.828.478

sum n or 4 FIG. 8

TUYERE' FOR A MELTING FURNACE- BACKGROUND OF THE INVENTION Thisinvention relates to a tuyere for a melting furnace, especially for ablast furnace.

Since hot air is blown at a high temperature into the furnace from thetuyere of the melting furnace, especially a blast furnace, and theportion of the tuyere projecting inside the furnace is exposed to themolten metal at high temperatures, the fuel burning in the furnace,etc., the tuyere must be forcibly cooled. In addi-' tion to this, sincehot air blown from the tuyere into the furnace must be supplied whilemaintaining its high temperature, care should be taken not to coolexcessively the inside of the tuyere.

Hithereto, however, it has notbeen possible to provide a tuyere whichsufficiently fulfils the above mentioned two conditions, namely, thecooling water should be smoothly circulated without causing anystagnation to sufficiently cool the tuyere to thereby prevent earlybreakage of the tuyere while the blown hot air should be maintained at ahigh temperature. The conventional tuyere has another defect in that itordinarily comes to the end of its life within three to five months.

SUMMARY OF THE INVENTION Therefore, this invention provides a tuyerewhich can overcome the above mentioned defects of the conventionaltuyere, namely, it can fulfil the above mentioned two conditions andhave a long service life.

It is an object of this invention to provide a tuyere for a meltingfurnace, which comprises inner andouter walls forming a water coolingspace therebetween, and an intermediate wall disposed in said watercooling space to divide the same into two inner and outer water coolingchambers, whereby cooling water is initially introduced into the outerwater cooling chamber and then circulated to the inner water coolingchamber, to thereby supply cooling water at a low temperature to theinside of the outer wall which is exposed to the highest temperature ofthe tuyere so that said outer wall is effectively cooled and preventedfrom early breakage by hot temperatures.

It is another object of this invention to provide a tuyere for a meltingfurnace, which further comprises a helical guide wall disposed in theouter water cooling chamber to form a helical passage therein, wherebythe cooling water introduced into the outer water cooling chamber andpassing through said helical passage circulates at a high speed at thevicinity of the top portion of the tuyere which must be most effectivelycooled, so that the vicinity of said top portion is effectively cooledand the loss of head of the cooling water is minimized.

It is a still further object of this invention to provide a tuyere for amelting furnace, wherein the vicinity of the top portion of the tuyereis cooled by cooling water passing through the helical passage in thewater cooling chamber at a high hydraulic pressure and at a high speedwhile the water cooling chamber of the rear portion of the tuyere issuppled with another cooling water at a low speed, whereby said rearportion is prevented from being cooled excessively.

It is a still further object of this invention to provide a tuyere for amelting furnace, which can be easily manufactured by welding therequired portions of the components, that is, hollow annular basemember, an inner wall, an outer wall, an intermediate wall and an edgewall, to thereby form an integrally assembled tuyere.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a central longitudinalsectional view of an embodiment of this invention;

FIG. 2 is a sectional view taken along the line II II of FIG. 1;

FIG. 3 is a sectional view taken along the line III III of FIG. 1;

FIG. 4 is a sectional view taken along the line IV IV of FIG. 1;

FIG. 5 is a sectional view taken along the line of V V of FIG. 1;

FIG. 6 is a central longitudinal sectional view of another embodiment ofthis invention and which is taken along the line VI VI of FIG. 7',

FIG. 7 is an end view of the tuyere taken from the left end in FIG. 6;

FIG. 8 is a sectional view taken along the line VIII VIII of FIG. 6;

FIG. 9 is a sectional view taken along the line IX IX of FIG. 6;

FIG. 10 is a sectional view taken along the line X X of FIG. 6 and whichis simplified so as to be easily understood.

DETAILED DESCRIPTION OF THE INVENTION in FIG. 2, the space inside thebase member 1 is divided by a pair of radial partitions 6 into a lowerchamber 19 and an upper chamber 20, the chambers 19 and 20 havingrespectively inlet ports 7 for receiving water and an outlet port 8 fordischarging water at the rear walls thereof (namely, the left side wallin FIG. 1) and having arcuate passages 9 and 10 at the forward wallthereof. These passages 9 and 10 are adapted to be connectedrespectively to an outer helical passage 13 and an inner helical passage14 described hereinafter.

The forward wall of the base member 1 (namely, the right side wall inFIG. I) is attached to the rear end surface of a inner wall 2 composedof a tapered cylindrical thick steel pipe by a weld 24.

An intermediate wall 5 composed of a steel plate or a copper plate isprovided at each of the outer and inner sides thereof with helical guidewalls 11 and 12 which are pitched at shorter spaces as they approach theforward side (namely, right side in FIG. 1) of the tuyere, and isattached at the top portion thereof to a circular partition 22 bywelding; The radii of the inner round surfaces of the inner guide wall12 and the partition 22 are equal to the outer radius of thecorresponding portion of the inner wall 2 while the radii of the outerround surfaces of the outer guide wall 11 and the partition 22 are equalto the inner radius of the corresponding portion of the outer wall 3.

As is shown in FIG. 4, an inclined partition 15 is attached to the frontsurface of the partition 22. The front surface of the partition 15 isadapted to be in contact with the inner surface of an end wall 4described hereinafter. An outlet port 17 is provided at the outer sideof the partition 15 while a passage 18 is provided at the inner side ofthe same. These openings 17 and 18 are adapted to be connected tohelical passages 13 and 14 which will be mentioned hereinafter.

The intermediate wall 5 as mentioned hereinabove is fitted to theoutside of the inner wall 2 and the rear end portion of the wall 5 isattached to the forward wall of the base member 1 by welding the portion23. Accordingly, the inner round surface of the guide wall 12 is closelyin contact with the outer round surface of the inner wall 2 to therebyform the inner helical passage 14 therebetween. And the rear end portionof the passage 14 being connected to the passage of the base member 1.

Further, the outer wall 3 in the form of a tapered cylinder and composedof a thick steel plate is fitted to the outside of the intermediate wall5. The rear end surface thereof is attached to the forward side wall ofthe base member 1 by the weld 25. Accordingly, the outer round surfaceof the guide wall 11 is closely in contact with the inner round surfaceof the outer wall 2 to thereby form the outer helical passage 13 betweenthese walls. The inlet portion 16 (FIG. 5) at the rear end of thepassage 13 is connected to the passage 9 of the base member 1.

Further, the annular end wall 4 is attached to the front surfaces ofsaid inner wall 2 and said outer wall 3 respectively by the welds 26 and27. The end wall 4 is composed of a thick copper plate and has beenmanufactured in advance to a predetermined shape by machinery such as alathe. As is mentioned hereinbefore, a passage 21 partitioned by thepartition is formed between the end wall 4 and the partition 22, wherecooling water changes its course from the outer helica passage 13 to theinner helical passage 14.

Now referring to the circulation flow of cooling water in the abovementioned embodiment of this invention, cooling water is supplied from afeed pipe (which is not shown in the drawings) through the inlet ports 7to the lower chamber 19 of the base member 1 and, then, is passed fromthe passage 9 at the side wall of the lower chamber 19 to the outerhelical guide passage 13. In the passage 13, cooling water is circulatedalong the guide wall 11 to cool the portion of the outer wall 3 whichportion is exposed to the inside of the furnace. Then, the cooling wateris directed through the outlet port 17 to the passage 21 to cool the endwall 4 and it passes through the passage 18 to the inner helical passage14. In the passage 14, the cooling water is circulated along the guidewall 12 to cool the inner wall 2 and, then, it flows through the passage10 into the upper chamber 20 of the base member 1. Thus, the coolingwater is discharged from the outlet port 8 to a discharge pipe (which isnot shown in the drawings);

connected thereto.

In the above described circulation flow of cooling water, cooling wateris circulated in the outer helical passage 13 to cool the outer wall 3and thereafterjt flows into the inner helical passage 14, to therebycool the inner wall 2 but to a higher temperature than it cools theouter wall 3. Therefore, the inner wall 2 is cooled to a suitable extentand there is not any risk that the hot air passing through the tuyerewill be cooled excessively.

Since the pitch of the guide wall 11 is made smaller as it advances tothe forward end of the tuyere, the width of the helical passage 13gradually becomes narrower in a direction toward the forward end.Therefore, when the cooling water flows into the passage 13, its flowingvelocity increases and it circulates at a high speed to cool the outerwall 3 so that the portion of the outer wall 3 projecting into theinside of the furnace and therefore being exposed to a high temperatureis sufficiently cooled. Cooling water which has passed through thepassage 13 as described hereinbefore flows at a higher speedin thepassage 21 which is formed along the end wall 4 and is narrower than thepassage 13. Thus, the end wall 4 which is exposed to the highesttemperature is also sufficiently cooled. Accordingly, the portion of theouter wall '3 which extends inside the 'fumace and the edge wall 4 aresufficiently cooled and therefore'the breakage of these portions is verydecreased to such an extent that it is not necessary to renew the tuyereeven after seven months service. Fur ther, it will be easy to design acooling means of the tuyere in accordance with the condition of thefurnace, because the flowing'velocity of cooling water can be optionallyadjusted by modifying the widths of the passages l3 and 21.

The tuyere as mentioned hereinbefore may be assembled by attaching tothe base member 1, by welding, the inner wall 2, the intermediate wall 5and the outer wall 3 in this order, and thereafter attaching the endwall 4 to the end portions of the inner wall 2 and the outer wall 3 bywelding. The guide walls 11 and 12, the partitions 15 and 22, etc.,which are necessary to form the passages 13, 14, 21, etc., will havebeen attached beforehand to the intermediate wall 5 by welding. Since,therefore, the guide walls 11 and 12 and the partitions 15 and 22respectively are closely in contact with the corresponding surfaceportions of the inner wall 2, outer wall 3 and end wall 4 only byattaching the intermediate wall 5 and the outer wall 3 to the basemember 1 by welding, with a result that the helical passages 13 and 14,passage 21, etc are formed, it is very easy to manufacture eachcomponent and to assemble the same.

Although, in the above mentioned embodiment of this invention, thehelical passages 13 and 14 are formed at both of the outside and insideof the intermediate wall 5 and throughout from the forward end to therear end thereof, it is sufficient to provide the helical passage 13only at the outside of the wall 5 and, if desired, only at the front endthereof.

FIG. 6 to FIG. 10 show another embodiment of this invention.

In FIG. 6, a hollow annular base member 31 is composed of a coppercasting or a steel casting. To the forward end of the base member 31, aninner wall 32 and an outer wall 33 each having a cylindrical form andcomposed of a material such as copper are integrally attached to form arear water cooling chamber 53 therebetween. The forward end portion ofthe water cooling chamber is closed with a partition 54. And a forwardmember 34 composed of a material such as copper is integrally attachedto said forward end portion. The forward member 34 is provided with anannular concavity which forms a forward water cooling chamber. At theforward position of this chamber, a partition 52 is secured. Further, acylindrical intermediate wall 35 is provided between the partitions 52and 54 to divide the forward water cooling chamber into inner and outerwater cooling chambers. As is shown in FIG. 9, to the front surface ofthe partition 52, an inclined partition 45 is attached, the frontsurface of which partition 45 is closely in contact with the innersurface of the forward member 34. An outlet port 47 is provided outsidethe partition 45 while a passage 48 is provided inside the same.

Further, a helical guide wall 41 is provided outside the intermediatewall 35 and between the partitions 52 and 54 to thereby form a helicalpassage 43, the forward side of which passage 43 is connected throughthe outlet port 47 to the passage 51 in front of the partition 52. Therear side of the passage 43 is connected through an opening in thepartition 54 to a water supply pipe 39 which is connected through therear water cooling chamber 53 to the inlet port 37 formed in the basemember 31.

To the inner water cooling chamber 55 of the front water coolingchamber, a drainage pipe 40 is connected through an opening formed inthe partition 54. The pipe 40 is connected to the outlet port 38 formedin the base member 31 while the forward side of the inner water coolingchamber 55 is connected through the passage 48 to the passage 51. At therear end portion of the base member 31, an inlet port 56 and an outletport 57 are provided, each of which is connected to the rear watercooling chamber 53. The inlet port 56 is connected to the water supplypipe 58 to open the top end thereof to the vicinity of the forwardportion of the water cooling chamber 53.

According to the above mentioned construction, the

cooling water for cooling the forward water cooling chamber is suppliedthrough the following course; inlet port 37 water supply pipe 39 helicalpassage 43 outlet port 47 passage 51 passage 48 inner water coolingchamber 55 drainage pipe 40 outlet port 38, and thereafter is dischargedfrom a drainage pipe (not shown) connected to the outlet port On theother hand, the cooling water which is supplied through the inlet port56 to the water supply pipe 58 flows in the rear water cooling chamber53 to fill the same and thereafter is discharged from the outlet port57.

In this embodiment, the cooling water is circulated in two separatecourses, namely, one course of the cooling water is circulated from theinlet port 37 and through the circular" passage 51 and thereafterdischarged from the outlet port 38 while the other course is circulatedfrom the inlet port 56 and through the rear water cooling chamber 53 andthereafter discharged from the outlet port 57. According to thisembodiment, the cooling water is supplied to the forward water coolingchamber is at a high pressure and a high speed, for the purpose ofeffectively cooling the vicinity of the top portion of the tuyere whichis exposed to the highest temperature. On the other hand, since thetemperature of hot air decreases if excessive cooling is applied, therear water cooling chamber 53 should be cooled while preventing such anexcessive cooling condition. However, by the above mentioned embodiment,cooling water can be supplied to the rear water cooling chamber 53 at alower pressure and a lower speed than it is supplied to the forwardwater cooling chamber, to thereby carry out an effective cooling.

Further, since cooling water supplied to the forward water coolingchamber is circulated through the helical passage 43 and the circularpassage 51 to the inner water cooling chamber 55, there is not causedany hold-up of water current, and the cooling water can be circulated ata high speed with little loss in head. Thus the top portion of thetuyere which is exposed to the highest temperature can be effectivelycooled. The cooling water can be also circulated at an optional speed byvarying the sectional area of the passage 43, etc. Further, even if thetop portion of the tuyere is broken to cause the leakage of water at theforward water cooling chamber, the operation can be carried on bymaintaining the circulation of water to the rear water cooling chamber53.

' While all components are attached together by welding in the abovementioned embodiments of this invention, they may be attached togetherby any other conventional means and the jointed portions may vary otherthan the jointed portion mentioned hereinbefore. It will be obvious tothose skilled in the art that various modifications of the presentinvention may be resorted to in a manner limited only by a justinterpretation of the following claims.

I claim:

1. Atuyere for-a melting furnace comprising inner and outer wallsforming a water cooling chamber therebetween, a partitiondisposed at aposition near the furnace side of said water cooling chamber to dividethe chamber into a forward water cooling chamber section at the furnaceside thereof and a rear water cooling chamber section at the oppositeside thereof, a cylindrical intermediate wall having an axis extendingin the same direction as those of said inner and outer walls and beingdisposed in said forward water cooling chamber section to divide theforward chamber section into an inner water cooling zone and an outerwater cooling zone, a helical guide wall disposed in said outer watercooling zone to form a helical passage for water, a water supply pipeand a drainage pipe respectively connected to said outer water coolingzone and inner water cooling zone, each pipe extending inside the rearwater cooling chamber section, and said rear water cooling chambersection being provided with an inlet port for receiving water and anoutlet port for discharging the same.

2. A tuyere as defined in claim 1, in which said inner and outer wallsare radially spaced, concentric tubular walls, and said partition is aradially extending annular wall extending between said inner and outerwalls.

1. A tuyere for a melting furnace comprising inner and outer wallsforming a water cooling chamber therebetween, a partition disposed at aposition near the furnace side of said water cooling chamber to dividethe chamber into a forward water cooling chamber section at the furnaceside thereof and a rear water cooling chamber section at the oppositeside thereof, a cylindrical intermediate wall having an axis extendingin the same direction as those of said inner and outer walls and beingdisposed in said forward water cooling chamber section to divide theforward chamber section into an inner water cooling zone and an outerwater cooling zone, a helical guide wall disposed in said outer watercooling zone to form a helical passage for water, a water supply pipeand a drainage pipe respectively connected to said outer water coolingzone and inner water cooling zone, each pipe extending inside the rearwater cooling chamber section, and said rear water cooling chambersection being provided with an inlet port for receiving water and anoutlet port for discharging the same.
 2. A tuyere as defined in claim 1,in which said inner and outer walls are radially spaced, concentrictubular walls, and said partition is a radially extending annular wallextending between said inner and outer walls.